Conductive resin composition, connection method between electrodes using the same, and electric connection method between electronic component and circuit substrate using the same

ABSTRACT

The present invention provides a conductive resin composition for connecting electrodes electrically, in which metal particles are dispersed in a flowing medium, wherein the flowing medium includes a first flowing medium that has relatively high wettability with the metal particles and a second flowing medium that has relatively low wettability with the metal particles, and the first flowing medium and the second flowing medium are dispersed in a state of being incompatible with each other. Thereby, a flip chip packaging method that can be applied to flip chip packaging of LSI and has high productivity and high reliability is provided.

This application is a division of U.S. Ser. No. 11/683,612, filed Mar.8, 2007 which application is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a conductive resin composition, aconnection method between electrodes using the same, and an electricconnection method between an electronic component and a circuitsubstrate using the same.

2. Description of Related Art

In recent years, due to an increase of density and an increase ofintegration of a semiconductor integrated circuit (LSI) that is used forelectronic equipment, an increase in the number of pins and narrowing ofa pitch of an electrode terminal of a LSI chip have proceeded rapidly.For packaging these LSI chips on circuit substrates, flip chip packagingis used widely in order decrease wiring delay. And, in this flip chippackaging, it is common that a solder bump is formed on an electrodeterminal of the LSI chip, and is connected to a connection terminalformed on the circuit substrate via the solder bump in one piece.

However, in order to package a next-generation LSI with the number ofelectrode terminals of more than 5,000 on a circuit substrate, whichbecomes finer, it is necessary to form a bump that corresponds to anarrow pitch of 100 μm or less, but a current technique for forming asolder bump is difficult to adapt to it.

Moreover, since it is necessary to form a large number of bumps thatcorrespond to the number of the electrode terminals, high productivityby shortening a mounted time of each chip also is required in order toreduce the cost.

Similarly, in the semiconductor integrated circuit, a peripheralelectrode terminal is changed into an area-disposed electrode terminalwith the increase of the electrode terminals. Moreover, due to therequirements for the increase of the density and the increase of theintegration, a semiconductor process is expected to proceed from present65 nm, and further to 45 nm, 32 nm.

As a result, the wiring becomes more finer, and a capacity between thewirings is increased, so that problems of an increase of a speed and aloss of power consumption become serious, and the demand for a decreaseof a dielectric constant (Low-K) of an insulation film between wiringlayers is increased further. Since such Low-K of the insulation film isrealized by treating an insulation layer material to be porous, amechanical strength thereof is low, which prevents a decrease of athickness of the semiconductor.

In addition, when structuring the area-disposed electrode terminal asdescribed above, there is a problem in strength on the porous film dueto the Low-K, and since an electrode is needed on an active area of thesemiconductor integrated circuit, it is difficult to form the bump onthe area-disposed electrode and achieve the flip chip packaging itself.Thus, a low-load flip chip packaging method, which corresponds to thedevelopment of the semiconductor process in the future, and is suitablefor a semiconductor with a small thickness and a high density, isdemanded.

Conventionally, as a technique for forming a bump, a plating method, ascreen printing method and the like are developed. The plating method issuitable for a narrow pitch, but requires complicated processes andresults in a problem in productivity. On the other hand, the screenprinting method has excellent productivity, but is not suitable fornarrowing a pitch from the standpoint of using a mask.

In the light of the problems described above, several techniques forforming a solder bump selectively on an electrode of a LSI chip or acircuit substrate have been developed recently. These techniques notonly are suitable for forming fine bumps, but also have excellentproductivity because of enabling the formation of the bumps in a lump,which attract attention as techniques that can be applied to packagingof the next-generation LSI on the circuit substrate.

For example, in a technique described in Patent Document 1, a solderpaste obtained by mixing conductive particles and flux is appliedsolidly onto a substrate having an electrode formed on a surfacethereof, and the substrate is heated, whereby the conductive particlesare melted so as to form a solder bump selectively on the electrode withhigh wettability.

Moreover, in the technique described in Patent Document 2, a paste-typecomposition (chemical reaction deposition-type solder) that contains anorganic acid lead salt and metal tin as main components is appliedsolidly onto a substrate on which an electrode is formed, and thesubstrate is heated, whereby a substitution reaction between Pb and Snis caused so as to deposit an alloy of Pb/Sn on the electrode of thesubstrate selectively.

By the way, the flip chip packaging using a conventional bump formationtechnique further requires a step of injecting a resin called anunderfill between the semiconductor chip and the circuit substrate so asto fix a semiconductor chip on the circuit substrate, after mounting thesemiconductor chip on the semiconductor substrate on which a bump isformed. Thus, after mounting the semiconductor chip on the circuitsubstrate and melting the solder bump so as to achieve an electricconnection, a mechanical strength is low, and it is unstable until theunderfill is cured completely.

Then, as a method for achieving an electric connection between theelectrode terminals of the semiconductor chip and the circuit substratethat face to each other, and fixing the semiconductor chip onto thecircuit substrate at the same time, a flip chip packaging technique (forexample, see Patent Document 3) using an anisotropic conductive materialis developed. This achieves the electric connection between theelectrode terminals of the semiconductor chip and the circuit substrateand the fixation of the semiconductor chip onto the circuit substrate atthe same time, by supplying a thermosetting resin containing conductiveparticles between the circuit substrate and the semiconductor chip so asto apply a pressure onto the semiconductor chip, and heating thethermosetting resin at the same time.

However, in the flip chip packaging using the anisotropic conductivematerial, since conduction between the facing electrode terminals isobtained by a mechanical contact between the conductive particles thatare dispersed uniformly in the resin, the conductive particles thatcontribute the conduction between the electrode terminals are limited toa part of the conductive particles contained in the resin. Moreover, thereliable electric connection between the conductive material and thefacing electrode terminal requires a certain load, and is not suitablefor packaging the area-disposed semiconductor integrated circuit usingthe porous film (Low-K).

Further, since the conductive particles that do not contribute to theconduction between the facing electrode terminals also can be a factorthat inhibits insulation between the adjacent electrode terminals, theflip chip packaging using the anisotropic conductive material hasnumerous problems to be solved in the light of the productivity and thereliability, for being applied to the next-generation LSI chip with thenumber of connection terminals of more than 5,000.

Further, for the purpose of preventing such conductive particles frombeing present between the adjacent electrode terminals, a method ofmelting and integrating solder particles that are dispersed uniformlyand collecting them between the electrode terminals is suggested (forexample, see Patent Document 4).

According to the present method, by disposing a conductive adhesivebetween facing terminals such as electrodes and heating it at atemperature that is higher than a melting point of the conductiveparticles and does not terminate the curing of the resin, the meltedconductive particles assume a state of being spread.

Further, the conductive particles that are melted are in a “wettingstate” on its terminal surfaces, and further, the conductive particlesare arranged so as to be in contact with each other and expanded, sothat the terminals are connected electrically.

[Patent Document 1] JP 2000-94179 A

[Patent Document 2] JP 1(1989)-157796 A

[Patent Document 3] JP 2000-332055 A

[Patent Document 4] JP 2004-260131 A

However, in the flip chip packaging using the anisotropic conductivematerial by the integration method of the melted conductive powdersdescribed above, by the physical contact of the conductive particles inwhich the melted conductive powders are dispersed uniformly in theresin, the respective conductive powders are integrated due to thewetting caused by the contact, and obtain the conduction between thefacing electrode terminals, and thus, unless a large amount of theconductive particles that contribute to the conduction between theelectrode terminals are present in the resin, the conduction cannot beobtained. That is, the melted conductive powders that are dispersed inthe resin are required to be present so as to have a probability to bein contact with each other, and redundant conductive powders also arerequired to be added so as to obtain the conduction between theelectrode terminals reliably.

Thus, also in the present method, only a part of the conductiveparticles contribute to the conduction. Moreover, the conductiveparticles that do not contribute to the conduction between the facingelectrode terminals are present, which can be a factor in inhibiting theinsulation between the adjacent electrode terminals.

That is, even the flip chip packaging using the anisotropic conductivematerial by the integration method of the melted conductive powders hasnumerous problems to be solved in the light of the reliability, forbeing applied to the next-generation LSI chip with the number of theconnection terminals of more than 5,000.

SUMMARY OF THE INVENTION

Therefore, with the foregoing in mind, it is an object of the presentinvention to provide a conductive resin composition that can be appliedto flip chip packaging of a next-generation LSI and has highproductivity and high reliability, a connection method betweenelectrodes using the same, and electric connection method between anelectronic component and a circuit substrate using the same.

The conductive resin composition of the present invention is aconductive resin composition for connecting electrodes electrically, inwhich metal particles are dispersed in a flowing medium, wherein theflowing medium includes a first flowing medium that has relatively highwettability with the metal particles and a second flowing medium thathas relatively low wettability with the metal particles, and the firstflowing medium and the second flowing medium are dispersed in a state ofbeing incompatible with each other.

The connection method between electrodes of the present invention is anelectric connection method between electrodes using a conductive resincomposition in which metal particles are dispersed in a flowing medium,the connection method including: preparing the conductive resincomposition in which the flowing medium includes a first flowing mediumthat has relatively high wettability with the metal particles and asecond flowing medium that has relatively low wettability with the metalparticles, and the first flowing medium and the second flowing mediumare dispersed in a state of being incompatible with each other;supplying the conductive resin composition between a plurality ofelectrodes that are arranged so as to face each other; disposing thefirst flowing medium in which the metal particles are dispersed betweenthe plurality of the electrodes by utilizing the wettability between theelectrodes and the first flowing medium; disposing the second flowingmedium in other region; and self-aggregating the metal particles betweenthe electrodes so as to achieve an electric connection selectively.

The connection method between an electronic component and a circuitsubstrate of the present invention is an electric connection methodbetween an electronic component and a circuit substrate for disposing asemiconductor chip having a plurality of electrode terminals so as toface the circuit substrate having a plurality of connection terminals,and electrically connecting the connection terminal of the circuitsubstrate and the electrode terminal of the semiconductor chip via aconductive resin composition, the electric connection method including:a first step of supplying the conductive resin composition in which afirst flowing medium that has relatively high wettability with the metalparticles and a second flowing medium that has relatively lowwettability with the metal particles are included, and the first flowingmedium and the second flowing medium are dispersed in a state of beingincompatible with each other, and disposing the semiconductor chip onthe circuit substrate to which the conductive resin composition issupplied so as to face each other at a predetermined gap, at a desiredposition of the connection terminal of the circuit substrate or theelectrode terminal of the semiconductor chip; a second step of holdingsuch that the first flowing medium in which the metal particles aredispersed is formed to be self-aggregated by an interfacial tensionbetween the plurality of the electrode terminals and the plurality ofthe connection terminals that are arranged so as to face each other, andthe second flowing medium is present in a region except for theplurality of the electrode terminals and the plurality of the connectionterminals that are arranged so as to face each other, in a stationarystate where the semiconductor chip and the circuit substrate face eachother; and a third step of curing the conductive resin composition thatis supplied between the circuit substrate and the semiconductor chip.The connection terminal of the circuit substrate and the electrodeterminal of the semiconductor chip are connected electrically by anaggregation of the metal particles contained in the self-aggregatedfirst flowing medium.

These and other advantages of the present invention will become apparentto those skilled in the art upon reading and understanding the followingdetailed description with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C are views explaining states of mixing a conductive resincomposition in one example of the present invention in a time series.

FIGS. 2A to 2E are cross-sectional views showing steps of a flip chippackaging method using a conductive resin composition in one example ofthe present invention.

FIGS. 3A to 3F are cross-sectional views showing steps of a flip chippackaging method in one example of the present invention.

FIG. 4 is a cross-sectional view showing a structure of a flip chippackage obtained in one example of the present invention.

FIG. 5 is a cross-sectional view showing a structure of a flip chippackage obtained in one example of the present invention.

FIG. 6 is a cross-sectional view showing a structure of a flip chippackage obtained in one example of the present invention.

FIG. 7 is a cross-sectional view showing a structure of a flip chippackage obtained in one example of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

According to the present invention, by using a conductive resincomposition, an electric connection can be achieved easily andselectively between electrode terminals of a circuit substrate and acircuit substrate, or electrode terminals of a circuit substrate and asemiconductor integrated circuit. By applying the conductive resincomposition onto whole regions of connection terminals and the electrodeterminals of the circuit substrate and an electronic component to beconnected, and arranging the circuit substrates and the electroniccomponents to be connected at a predetermined interval such that theelectrode terminals and the connection terminals of the electroniccomponent or the circuit substrate face each other, a first flowingmedium containing metal particles is self-aggregated by a surfacetension between the predetermined connection terminal and the electrodeterminal, and the electric connection can be achieved between theelectrode terminal and the connection terminal of the circuit substratesor the electronic component and the circuit substrate by contact of theself-aggregated metal particles. That is, the self-aggregation can beachieved by utilizing the incompatibility between the first flowingmedium that has relatively high wettability with the metal particles andthe second flowing medium that has relatively low wettability with themetal particles. Thereby, since the metal particles can be aggregatedbetween the desired electrode terminal and the connection terminal, themetal particles are not present in an unnecessary part other than theelectrode terminal and the connection terminal, thereby securingexcellent insulation reliability.

Moreover, since the electrode terminal and the connection terminal ofthe circuit substrate or the electronic component have predeterminedthicknesses, a gap between the circuit substrate and the electroniccomponent is narrowed between the electrode terminals, and theself-aggregation can be achieved at room temperature by a surfacetension of the first flowing medium. Thereby, the self-aggregation ofthe metal particles can be achieved at a low temperature withoututilizing the wettability of the melted metal particles, which iseffective from the standpoint of the environmental issue.

Further, by heating so as to melt the metal particles and wettingbetween the electrode terminal and the connection terminal in the stateof self-aggregating them by the surface tension of the first flowingmedium at room temperature, an electric connection that has lowerresistance and higher reliability can be obtained. Moreover, at the sametime, by thermosetting the second flowing medium by heating, theelectric connection by the metal particles and sealing between theelectronic component and the circuit substrate can be achieved at thesame time, thereby realizing the electric connection with highproductivity.

The metal particles have relatively high wettability with the firstflowing medium and relatively low wettability with the second flowingmedium, and thus are moved selectively toward the first flowing medium.Thus, the metal particles that are necessary for the electric connectioncan be reduced to a minimum. Moreover, the metal particles are notpresent in an unnecessary part, thereby securing the excellentinsulation.

In the present invention, the “wettability” can be measured by forming afoil or a plate of the same material as the metal particles, andmeasuring a contact angle of each of the flowing media on a surface ofthe foil or the plate.

Moreover, the “relative” is a term showing whether it is high or low ina relationship between the first flowing medium and the second flowingmedium. When the wettability is high, the metal particles are likely tobe self-aggregated.

Further, the “flowing medium” is a medium showing a flowing state wherethe metal particles can be moved when electrically connecting theelectrodes by using the conductive resin composition at room temperature(25° C.) or heating it. The present invention provides a connectionmethod between the electrodes by supplying the conductive resincomposition, which is a flowing medium, between the plurality of theelectrodes that are arranged so as to face each other by a method suchas application and printing at room temperature, and a viscosity of theflowing medium for achieving such supplying and a viscosity that doesnot inhibit the aggregation caused by the wetting of the first flowingmedium in which the metal particles are dispersed preferably are 1000Pa·s (pascal second) or less. Moreover, a viscosity, at which the metalparticles that are dispersed in the first flowing medium cannot bedispersed due to sedimentation or the like, is 10 Pa·s or less. Thus,the viscosity of the “flowing medium” of the present inventionpreferably ranges from 10 Pa·s to 1000 Pa·s.

The present invention can achieve the electric connection between theelectrodes effectively and reasonably by using the conductive resincomposition in which the first flowing medium and the second flowingmedium are dispersed in a state of being incompatible with each other.More specifically, the electric connection can be achieved selectivelybetween the connection terminal and the electrode terminal of thecircuit substrate and the circuit substrate or those of the circuitsubstrate and the semiconductor integrated circuit. The conductive resincomposition is applied onto a whole region of the connection terminal ofthe circuit substrate to be connected, and the electrode terminal andthe connection terminal of the electronic component to be connected arearranged so as to face with each other. Thereby, the first flowingmedium containing the metal particles is self-aggregated by a surfacetension between the predetermined connection terminal and thepredetermined electrode terminal. By the contact of the self-aggregatedmetal particles, the electric connection can be achieved between theelectrode terminal and the connection terminal of the circuit substratesor those of the electronic component and the circuit substrate.

It is preferable that, in the conductive resin composition, the firstflowing medium, the second flowing medium and the metal particles aredispersed when being mixed, and the metal particles are dispersed in thefirst flowing medium and the first flowing medium and the second flowingmedium are dispersed in a stationary state.

The surface tension of the first flowing medium is preferably higherthan the surface tension of the second flowing medium.

It is preferable that the flowing medium of the conductive resincomposition is composed of a thermosetting resin, and the metalparticles are made of solder, and have a melting point that is lowerthan a curing temperature of the thermosetting resin.

It is also possible that the first flowing medium of the conductiveresin composition is composed of a thermoplastic resin, and the secondflowing medium is composed of a thermosetting resin.

It is also possible that the first flowing medium of the conductiveresin composition is composed of a thermosetting resin, and the secondflowing medium is composed of a photocurable resin.

It is preferable that the conductive resin composition is suppliedbetween an electronic component and the circuit substrate whichrespectively have a plurality of electrodes that are arranged so as toface each other, the first flowing medium in which the metal particlesare dispersed is present between the plurality of the electrodeterminals and the plurality of the connection terminals that arearranged so as to face each other, and the second flowing medium ispresent in other region.

It is preferable that the conductive resin composition is present withthe melted metal particles in the first flowing medium between theplurality of the electrode terminals and the plurality of the connectionterminals that are arranged so as to face each other between theelectronic component and the circuit substrate, and the electricconnection is achieved between the plurality of the electrode terminalsand the plurality of the connection terminals.

In the electric connection method of the present invention, it ispreferable to form an organic layer for decreasing the wettability of apart except for a part between the electrodes. The organic layer fordecreasing the wettability may be a water-repellent or oil-repellentorganic layer made of, for example, a silicone-acrylic copolymer or afluorine-acrylic copolymer. Further, it is preferable that theelectronic component and/or the circuit substrate respectively have theplurality of the electrode terminals and the plurality of connectionterminals that are arranged so as to face each other, a first region anda second region that has high wettability with the flowing medium thanthe first region are present on a main surface of the electroniccomponent or the circuit substrate, and the organic layer for decreasingthe wettability is present in the first region. Moreover, the secondregion that has the high wettability with the flowing medium than thefirst region may be the plurality of the electrode terminals and theplurality of the connection terminals, which are arranged so as to faceeach other, of the electronic component and/or the circuit substrate.

In the present invention, the electronic component preferably is asemiconductor device that has a plurality of electrode terminals.Moreover, the electronic component preferably is composed of a circuitsubstrate that is constituted of a plurality of wiring patterns and aplurality of electrode terminals.

Moreover, the flowing medium is a liquid, and a solvent that can bedissolved only in the first flowing medium or the second flowing mediummay be added thereto.

Moreover, it is preferable that the metal particles are in contact witheach other such that the aggregation of the metal particles composes theconductive resin composition.

Moreover, between the second step and the third step, a step of heatingthe conductive resin composition containing the aggregation of the metalparticles that are self-aggregated between the connection terminal ofthe circuit substrate and the electrode terminal of the semiconductorchip so as to melt the metal particles that are contained in the firstflowing medium further may be included.

The first step preferably includes, after supplying the conductive resincomposition on the circuit substrate, arranging the semiconductor chipso as to face the circuit substrate such that the connection terminal ofthe circuit substrate and the electrode terminal of the semiconductorchip have a desired gap. In the first step, the surface of the circuitsubstrate except for the electrodes preferably is subjected towater-repellent treatment or oil-repellent treatment in advance.

A content of the metal particles, the first flowing medium and thesecond flowing medium preferably is within a range of the metalparticles: 4 wt % to 40 wt %; the first flowing medium: 10 wt % to 20 wt%; and the second flowing medium: 40 wt % to 76 wt %.

The electric connection method of the present invention is suitablyapplied to flip chip packaging of an LSI chip on a circuit substrate andpackaging of the circuit substrates, and in the case where the metalfine particles are 4 wt % or more, when they are dispersed in the firstflowing medium and are self-aggregated, the contact of the metal fineparticles with each other becomes sufficient, and a secure electricconnection can be obtained. Moreover, in the case where the metal fineparticles are 40 wt % or less, they may be present substantially only inthe first flowing medium, and are not present or only marginally presentin an unnecessary part, thereby obtaining the electric insulation.Because of the similar reason, the first flowing medium is set so as tobe self-aggregated in an electrically connected part, and thus the rangebetween 10 wt % to 20 wt % is preferable.

Arbitrary solder particles may be selected to be used. For example,solder particles listed in Table 1 below can be exemplified. Materialsshown in Table 1 can be used alone or in combination as appropriate.

TABLE 1 melting point (solidus curve) composition of solder particle (°C.) Sn—58Bi 139 Sn—37Pb 183 Sn—9Zn 199 Sn—3.0Ag—0.5Cu 217 Sn—3.5Ag 221Sn—0.7Cu 228 12Sn—2.0Ag—10Sb—Pb 240

The melting point of the solder particles preferably ranges from 100° C.to 300° C., and more preferably ranges from 139° C. to 240° C. as shownin Table 1. If the melting point is less than 100° C., a problem tendsto occur in durability. If the melting point is more than 300° C., theselection of the resin becomes difficult.

An average volume particle diameter of the solder particles preferablyranges from 1 μm to 30 μm, and more preferably ranges from 5 μm to 20μm. If the average volume particle diameter is less than 1 μm, themelting of the solder particles becomes difficult due to surfaceoxidation, and it tends to take a significantly long period of time toform an electric connector. If the average volume particle diameter ismore than 30 μm, it becomes difficult to obtain the electric connectordue to sedimentation. Herein, the average volume particle diameter canbe measured by using a commercially available particle size distributionmeter. For example, the measurement can be carried out by using a laserdiffraction particle size meter produced by HORIBA, Ltd. (product name:“LA920”), a laser diffraction particle size meter produced by ShimadzuCorporation. (product name: “SALD2100”) or the like.

An embodiment of the present invention will be described below withreference to drawings. In the drawings described below, the componentshaving substantially the same functions are denoted by the samereference numerals so as to simplify their explanations. Moreover, thepresent invention will not be limited to the below embodiment.

FIGS. 1A to 1C are cross-sectional views showing a structure of theconductive resin composition according to the embodiment of the presentinvention.

Firstly, as shown in FIG. 1A, a conductive resin composition 10 of thepresent invention is present in a flowing medium in a state where metalparticles 13 are dispersed. The flowing medium is composed of a firstflowing medium 12 that has high wettability with the metal particles 13and a second flowing medium 11 that has low wettability with the metalparticles 13. Due to sufficient dispersion of each of the componentsthat compose the conductive resin composition 10, the flowing media 12and 11 are dispersed without being dissolved, and the metal particles 13are present in a state where a part of the metal particles 13 are wettedwith the second flowing medium 12. In this state, the first flowingmedium and the second flowing medium that contain the metal particlesare mixed, and the first flowing medium 12 and the second flowing medium11 are separated after a lapse of a predetermined time because they areincompatible with each other. At this time, the first flowing medium 12that has the high wettability includes a relatively large amount of themetal particles 13, and the second flowing medium 11 that has the lowwettability includes relatively less metal particles 13. As describedabove, the wettability of the flowing media with the metal particles 13is measured.

FIGS. 1B and 1C show a change in time series of the conductive resincomposition 10 in such a condition in a stationary state, after beingdropped onto a substrate or the like. FIG. 1C shows a state of theconductive resin composition 10 that is allowed to be in the stationarystate and then is let stand for a sufficient period of time, and FIG. 1Bshows a state after a lapse of time (for example, after about 20 secondsfrom the time when letting the conductive resin composition 10 stand).

In FIG. 1B, a large part of the metal particles 13 are taken into thefirst flowing medium 12 that has the excellent wettability, and only asmall amount of the metal particles 13 are present in the second flowingmedium 11. Moreover, since the first flowing medium 12 and the secondflowing medium 11 are not dissolved with each other, they are separatedcompletely, and the first flowing medium 12 becomes wet and aggregatedsequentially. Subsequently, after letting it stand for a sufficientlylong period of time (for example, after about 1 minute from the time ofstarting to let it stand), as shown in FIG. 1C, the first flowing medium12 in which the metal particles 13 are complemented with wettability isenlarged in size extremely, and assumes a state where a bubble-shapedaggregation that contains the metal particles 13 and is independent inthe second flowing medium 11 is dispersed.

As the metal particles, high melting point metal powders such as copper,silver and gold, low melting point metal powders such as tin, indium,bismuth and zinc, and alloy powders of them can be used. Particularly,solder particles exemplified in Table 1 described above are preferable.Powders that are subjected to surface treatment for securing thewettability with the first flowing medium can be used. As the surfacetreatment, for example, water-repellent treatment, hydrophilizingtreatment and the like can be used. Further, it is preferable that acontent of the metal particles ranges from 4 wt % to 40 wt %, a contentof the first flowing medium ranges from 10 wt % to 20 wt %, and thesecond flowing medium ranges from 40 wt % to 76 wt %. According to suchcontents, more metal particles than those required for aggregating inthe first flowing medium due to the wettability and obtaining anelectric connection due to the aggregation in the first flowing mediumare not necessary.

Moreover, as the first flowing medium, a thermosetting resin that is aliquid before the use and is cured by heat, a thermoplastic resin thatis softened or melted in a state of being heated, an organic solventthat is a liquid at room temperature and the like can be used. As thethermosetting resin, an epoxy resin, an acrylic resin, a silicone resin,polyimide and the like can be used. As the thermoplastic resin,polyvinylbutyral (a butyral resin), polybutadiene and the like can beused. As the organic solvent, alcohols such as ethanol, butanol andglycerin, ketones and the like can be used.

Whereas, as the second flowing medium, various kinds of resins that arenot dissolved in the first flowing medium, and organic solvents can beused. For example, an epoxy resin, polyimide and the like that arethermosetting resins can be used.

A content ratio of the first flowing medium 12 and the second flowingmedium 11 varies according to a size and the number of the connectionterminals 15 of the circuit substrate 14 that are electricallyconnected, but it is preferable that, when the conductive resincomposition is assumed to be 100 wt %, the first flowing medium 12ranges from 10 wt % to 20 wt %, and the second flowing medium 11 rangesfrom 40 wt % to 76 wt %.

Moreover, it is preferable that a surface tension of the first flowingmedium 12 is higher than a surface tension of the second flowing medium11, and the self-aggregation can be achieved between the connectionterminal 15 and the electrode terminal 15 of the circuit substrate 14and a semiconductor chip 16 with priority, according to the surfacetension of the first flowing medium 12.

FIGS. 2A to 2E are cross-sectional views showing basic steps of a flipchip packaging method as one example of the present invention.

Firstly, as shown in FIG. 2A, a substrate (a circuit substrate) 14having a plurality of the connection terminals 15 is provided. Otherthan the connection terminals 15, a wiring pattern is provided, which isnot illustrated in FIG. 2A. Next, as shown in FIG. 2B, in a desiredregion of the connection terminal 15 on a surface of the circuitsubstrate 14, the conductive resin composition 10 including the firstflowing medium 12 and the second flowing medium 11 that contain themetal particles 13 is supplied by using a dispenser 20.

Herein, the metal particles 13 are dispersed uniformly in the conductiveresin composition 10, and it is preferable that the conductive resincomposition 10 is mixed to be uniform sufficiently in the dispenser 20,and has a viscosity having flowability at room temperature.

Next, as shown in FIG. 2C, the connection terminal 15 of the substrate14 and the electrode terminal 12 of the semiconductor chip 16 are fixedso as to face each other and maintain a constant gap. At this time, theconductive resin composition 10 on the connection terminal 15 of thesubstrate 14 is extruded slightly, whereby the gap between thesemiconductor chip 16 and the circuit substrate 14 is filled with theconductive resin composition 10.

Incidentally, the connection terminal 15 of the substrate 14 and theelectrode terminal 17 of the semiconductor chip 16 are not in contactdirectly with each other, and the conductive resin composition 10remains between the facing terminals.

Moreover, the conductive resin composition 10 may be supplied so as tofill in the gap between the semiconductor chip 16 and the substrate 14,after disposing the terminals 15 and 17 so as to face each other.

From this state, as shown in FIG. 2D, in the conductive resincomposition 10 that is present in the gap between the semiconductor chip16 and the circuit substrate 14, similarly to the behavior from FIG. 1Ato FIG. 1C, the first flowing medium 12 that contains the metalparticles 13 with the wettability aggregates gradually, is separatedfrom the second flowing medium 11, and aggregates at a protrudingportion of the connection terminal 15 of the circuit substrate 14 by theinterfacial tension. The metal particles 13 that are dispersed in thefirst flowing medium 12 can obtain an electric connection due to theaggregation of the metal particles in the first flowing medium.

Further, as shown in FIG. 2E, by curing or solidifying the first flowingmedium and the second flowing medium by heating, the electric connectionby the metal particles 13 and sealing between the semiconductor 16 andthe circuit substrate 14 can be achieved at the same time. Referencenumeral 11′ denotes an insulating resin that is solidified or cured.

Moreover, by melting the metal particles 13 by heating after the stepshown in FIG. 2D, an electric connection that has further lowerresistance and is secure can be obtained.

Next, FIGS. 3A to 3F are cross-sectional views showing basic steps of aflip chip packaging method as one example of the present invention.

Firstly, as shown in FIG. 3A, the substrate (the circuit substrate) 14that has a plurality of the connection terminals 15 is provided. Otherthan the connection terminals 15, a wiring pattern is provided, althoughmembers other than the connection terminals 15 are not illustrated inFIG. 3A. Next, FIG. 3B is a view showing a step of applyingwater-repellent treatment at a desired position on the circuit substrate14. For example, the water-repellent treatment is achieved on a surfaceof the substrate 14, by applying a resist on the surface.

Next, by leaving a region that serves as the connection terminals 15,the resist is patterned, a water-repellent film (for example, productname of “EGC-1700 electronic coating agent”; produced by Sumitomo 3MLimited) subsequently is applied onto a surface of the substrate 14while using the resist as a mask, and thereafter, the resist is liftedoff.

As a result, as shown in FIG. 3C, an organic film (a water-repellentfilm) 19 having water repellency remains on the surface of the substrate14 except for the connection terminals 15, and an interfacial tensionbetween the surface and the first flowing medium 12 containing the metalparticles 13 can be decreased.

On the circuit substrate 14 on which a water-repellent organic film 19is formed as described above, the conductive resin composition 10 issupplied by using the dispenser 20, similarly to the case of FIG. 2.

Next, as shown in FIG. 3D, the connection terminal 15 of the substrate14 on which the water-repellent organic film 19 is formed and theelectrode terminal 12 of the semiconductor chip 16 are fixed so as toface each other and maintain a constant gap. At this time, theconductive resin composition 10 on the connection terminal 15 of thesubstrate 14 is extruded slightly, and as a result, the gap between thesemiconductor chip 16 and the circuit substrate 14 is filled with theconductive resin composition 10.

From this state, as shown in FIG. 3E, in the conductive resincomposition 10 that is present in the gap between the semiconductor chip16 and the circuit substrate 14, similarly to the behavior from FIG. 1Ato FIG. 1C, the first flowing medium 12 that contains the metalparticles 13 with high wettability aggregates gradually, is separatedfrom the second flowing medium 11, is not wetted with thewater-repellent organic film 19 that is formed on the circuit substrate14 except for the connection terminals, and as a result, aggregates atthe connection terminals 15 by the interfacial tension. The metalparticles 13 that are dispersed in the first flowing medium 12 canobtain an electric connection due to the aggregation of the metalparticles in the first flowing medium.

Further, as shown in FIG. 3F, by curing or solidifying the first flowingmedium and the second flowing medium by heating, the electric connectionby the metal particles 13 and sealing between the semiconductor 16 andthe circuit substrate 14 due to the solidification of the flowing mediumcan be achieved at the same time. Reference numeral 11′ denotes aninsulating resin that is solidified or cured.

Moreover, the metal particles 13 are melted by heating similarly, andthe electric connection can be obtained. In the case of obtaining theelectric connection by melting the metal particles 13, the first flowingmedium of the flowing media may be water, and the second flowing mediumthereof may be a solvent.

The reason for this is because water and a solvent that are presentbetween the circuit substrate 14 and the semiconductor chip 16 arewashed out and removed, and thereafter, a sealing resin is suppliednewly and is cured, whereby the sealing resin with higher reliabilitycan be selected. A similar effect can be obtained, if the first flowingmedium of the flowing media is oil and the second flowing medium thereofis water.

As described above, in the conductive resin composition of the presentinvention that is supplied into the gap between the semiconductor chip16 and the circuit substrate 14, the aggregation of the metal particles13 that are self-aggregated by the interfacial tension between thefacing terminals by the effect of the first flowing medium 12 and thesecond flowing medium 11 that contain the metal particles 13, and arecontained with the wettability in the self-aggregated first flowingmedium 12 can form a connector that can provide the electricalconnection between the connection terminal and the electrode terminalselectively.

Thus, the metal particles 13 contained in the conductive resincomposition 10 can be utilized effectively. Moreover, since the firstflowing medium 12 containing the metal particles 13 is not presentbetween the adjacent terminals, the insulation between the adjacentterminals can be increased, and a flip chip package with highreliability can be realized.

Further, since the connector (the first flowing medium 12 containing themetal particles 13) for electrically connecting the connection terminal15 and the electrode terminal 17 can be formed with self-aggregation, itcan be applied also to narrow-pitched flip chip packaging of thenext-generation LSI.

In addition, by self-aggregating the first flowing medium 12 thatcontains the metal particles 13 between the connection terminal 15 andthe electrode terminal 17, and curing the self-aggregated first flowingmedium 12 and the second flowing medium 11 at the same time, theelectric connection can be achieved between the connection terminal 15and the electrode terminal 17 of the semiconductor chip 16 and thesubstrate 14, and the semiconductor chip 16 and the substrate 14 arefixed with the cured flowing medium 11′ at the same time, therebyrealizing the flip chip package with high productivity.

FIG. 4 is an enlarged cross-sectional view of the semiconductor chip 16packaged on the circuit substrate 14 that is obtained by the steps ofFIGS. 2A to 2E. The cross-sectional view shows a state where the firstflowing medium 12 containing the metal particles 13 is self-aggregatedbetween the connection terminal 15 of the circuit substrate 14 and theelectrode terminal 17 of the semiconductor chip 16, the circuitsubstrate 14 and the semiconductor chip 16 are fixed with the firstflowing medium 12 and the second flowing medium 11, and further, theconnection terminal and the electrode terminal 17 are connectedelectrically by the metal particles 13 that are aggregated in the firstflowing medium 12.

Similarly, FIG. 5 is a cross-sectional view showing a state where themetal particles 13 in the first flowing medium 12 are melted, and theconnection terminal 15 and the electrode terminal 17 are metal-connectedby a melted metal 18.

Moreover, FIG. 6 shows a state where the water-repellent organic film 19that is a water-repellent film having water repellency is formed at adesired position on the circuit substrate 14, the first flowing medium12 is self-aggregated on the part of the connection terminal 15 of thecircuit substrate 14 except for the water-repellent organic film 19, andthe electric connection is obtained by the metal particles 13 that areaggregated in the self-aggregated first flowing medium 12.

Similarly, FIG. 7 is a cross-sectional view showing a state where themetal particles 13 in the first flowing medium 12 are melted, and theconnection terminal 15 and the electrode terminal 17 are metal-connectedby the melted metal 18.

According to the structure of the present invention, in the firstflowing medium containing the metal particles 13, by applying thewater-repellent organic film 19 (water-repellent treatment) onto thesurface of the substrate 14 (or the semiconductor chip 16) in advance,the self-aggregation of the first flowing medium 12 between theterminals can be carried out smoothly.

Example 1

An example shown in FIGS. 2A to 2E will be described below specifically.As the circuit substrate 14 of FIG. 2A, a four-layer wiring glass epoxyresin substrate (produced by Panasonic Electronic Devices Co., Ltd.,ALIVH, registered trademark) was used, and a semiconductor chip (asilicon memory semiconductor, thickness: 0.3 mm, length: 10 mm, width:10 mm, having the electrode terminal 15 equivalent to the circuitsubstrate 14) was packaged on a wiring layer (diameter: 50 μm, pitch:100 μm, 352 terminals on its periphery) serving as the connectionterminal 15 on a part of a wiring pattern of a surface layer made of acopper foil. Incidentally, on the connection terminal 15 and the wiringpattern (not illustrated) of the circuit substrate 14, nickel wasapplied, and gold plating was applied further thereon.

Subsequently, as shown in FIG. 2B, the conductive resin composition 10of the present invention was supplied by using the dispenser 20. As themetal particles 13 of the conductive resin composition, solder (producedby Senju Metal Industry Co., Ltd., Sn-3.0 Ag-0.5 Cu, melting point: 217°C.) was used. An average volume particle diameter of solder particleswas 12 μm, which was measured by using a particle size distributionmeter.

Moreover, as the first flowing medium 12, an epoxy resin (produced bySANYU REC CO. LTD., a liquid epoxy resin GRS-811) was used, and as thesecond flowing medium 11, a silicone resin (produced by Shin-EtsuChemical Co., Ltd, curable liquid silicone KR285) was used. A contentratio will be described below.

a) metal particle 13: solder powder (Sn-3 Ag-0.5 Cu) 15 wt %

b) first flowing medium 12: epoxy resin 15 wt %

c) second flowing medium 11: silicone resin 70 wt %

The above-described materials were mixed while being stirred by using akneader. The conductive resin composition manufactured by mixing was putinto the dispenser 20, and was applied on a packaging part of thesemiconductor chip 16 of the circuit substrate 14. At this time, thedispenser 20 that has a function of stirring was used such that therespective materials were not separated. The conductive resincomposition was supplied while being controlled to have a constantthickness of about 40 μm.

At this time, the conductive resin composition may be supplied so as toscan the region on which the semiconductor chip 16 was packaged in orderto apply it on the whole region uniformly, or may be dispensed in anappropriate shape such as a letter and a mark.

In the state where the conductive resin composition 10 was supplied onthe circuit substrate 14 as described above, the semiconductor chip 16was positioned swiftly and was held so as to provide a predetermined gap(thickness: 30 μm) (FIG. 2C).

The conductive resin composition 10 that was supplied at this time wasin contact with the surface of the semiconductor chip 16, and an excessof the conductive resin composition 10 was squeezed out from thesemiconductor chip 16.

By maintaining this state for about 10 seconds, the first flowing medium12 and the second flowing medium 11 in the conductive resin composition10 were separated, and the metal particles 13 having excellentwettability came to be contained in the first flowing medium 12.Further, after a lapse of about 10 seconds, the first flowing medium 12containing the metal particles 13 aggregated slowly, and aggregated atthe electrode that protruded on the circuit substrate 14, that is, theconnection terminal 15 (FIG. 2D).

Further, as shown in FIG. 2E, by heating (170° C.) the whole of thecircuit substrate 14, the semiconductor chip 16 and the conductive resincomposition 10 and maintaining as they were (30 seconds), the firstflowing medium 12 and the second flowing medium 11 were cured by theheat. Then, the metal particles 13 in the first flowing medium 12aggregated between the connection terminal 15 and the electrode terminal17, thereby achieving an electric connection. At the same time, by thecuring of the first and second flowing media, the sealing between thecircuit substrate 14 and the semiconductor chip 16 could be achieved.

Moreover, by reheating (230° C.) those whose electric connection andsealing were completed, the solder that was the aggregated metalparticles 13 was melted, thereby achieving a connection with furtherdecreased resistance (FIG. 5).

In the package manufactured thereby, a fixed portion of the circuitsubstrate 14 and the semiconductor chip 16 was flexible, and had afunction to relax a stress that was caused by a thermal shock or thelike, thereby providing high reliability. Moreover, since the electricconnection was achieved by metal connection by melting of solder, astrong connecting condition could be maintained.

Further, since the epoxy resin that was the first flowing medium wascured on a melted solder-side surface, and functions to relax thethermal stress that was applied to the solder and suppress plasticdeformation that was applied to the solder, the package with exceedinglyhigh reliability could be obtained.

Example 2

An example shown in FIGS. 3A to 3F will be described below specifically.The circuit substrate 14 and the semiconductor chip 16 used in thepresent example were similar to those used in Example 1.

Firstly, in a region on the circuit substrate 14 except for the part ofthe connection terminal 15, the water-repellent organic film 19 that hadlow wettability with the first flowing medium 12 was formed. Morespecifically, a photosensitive water-repellent resist was used as thewater-repellent organic film 19.

The photosensitive water-repellent resist (produced by NIPPON PAINT Co.,Ltd, a silicone-acrylic block copolymer) was a photocurablewater-repellent material, and had a microphase-separated structure thatwas constituted of a “sea” composed of an acrylic chain and acrosslinking agent (isocyanate, melamine or the like) and an “island”composed of a silicone chain. According to this “sea and island”structure of the silicone resin that exhibited the water repellency, thewater repellency could be exhibited.

The specific method for forming the water-repellent organic film 19included: dropping the photosensitive water-repellent resist onto thecircuit substrate 14; applying it by spin coating so as to provide afilm thickness of 1.5 μm; and prebaking by heat treatment at 120° C. for30 minutes.

Thereafter, it was exposed to UV by using a photomask so as to provide apattern that was inverse to that of the above-described connectionterminal 15. An exposure value was 300 mj/cm² (wavelength of 350 nm),and it was prebaked again at 120° C. for 30 minutes.

Subsequently, a part (region of the connection terminal 15) that was notexposed was removed by development with diethyleneglycolmethylether, andonly a part to be provided with the water repellency was left. This wassubjected to heat treatment at 120° C. for 10 minutes, thereby beingcured completely (FIG. 3B).

On the circuit substrate 14 on which the thus manufacturedwater-repellent organic film 19 is formed, the conductive resincomposition 10 as described below was applied to a desired position byusing the dispenser 20.

-   -   a) metal particle: produced by MITSUI MINING & SMELTING CO.,        LTD. (Sn powder, average particle diameter: 2 μm); 10 wt %    -   b) first flowing medium: pure water; 15 wt %    -   c) second flowing medium: (epoxy resin 70 wt %+toluene 30 wt %);        75 wt %

The conductive resin composition 10 obtained by mixing theabove-described materials was applied by using the dispenser 20 as shownin FIG. 3C, the semiconductor chip 16 was disposed similarly to Example1, and the first flowing medium 12 containing the metal particles 13 wasself-aggregated between the connection terminal 15 and the electrodeterminal 17 over a course of time. In a mechanism in which the firstflowing medium (pure water) was self-aggregated, the first flowingmedium was water, the second flowing medium was a liquid epoxy resin inwhich toluene was dissolved, and the first and second flowing media werenot dissolved with each other and thus were separated over a course oftime. At this time, since the metal particles (Sn) were subjected tosurface treatment for obtaining a hydroxyl group on a surface thereof soas to have excellent wettability with water, the Sn powders were takeninto the pure water easily. Moreover, since the water-repellent organicfilm 19 as the organic film was formed on the circuit substrate 14 asdescribed above, the pure water that was the separated first flowingmedium was not wetted with the water-repellent organic film 19, and wasself-aggregated at the connection terminal 15 on which thewater-repellent organic film 19 was not present (FIG. 3E).

In the pure water that was the self-aggregated first flowing medium, theSn powders as the metal particles were aggregated. The thusself-aggregated package was volatilized by being maintained at 100° C.,which is a temperature for volatizing the pure water and the toluenethat was dissolved in the epoxy resin, for 30 minutes.

Further, it was maintained at 200° C. for 60 seconds so as to cure theepoxy resin that was the second flowing medium, thereby fixing thecircuit substrate 14 and the semiconductor chip 16. Further, by heatingat 250° C. for 20 minutes, the aggregated Sn powders were melted so asto connect between the connection terminal 15 and the electrode terminal17 of the semiconductor chip.

Thereby, the fixing between the circuit substrate 14 and thesemiconductor chip 16, and the electric connection between theconnection terminal 15 and the electrode terminal 17 could be achievedat the same time.

Herein, the flowing media and the metal particles of the conductiveresin composition that are used in the flip chip packaging method of thepresent invention are not limited particularly, but materials describedbelow can be used, respectively.

As the flowing medium, as described above, a thermosetting resin such asan epoxy resin, a phenol resin and a silicone resin, a thermoplasticresin such as a fluorocarbon resin, a polyimide resin and a polyamideresin, a photocurable (ultraviolet-curable) resin, and materialsobtained by combining them can be used, but it is preferable to have aviscosity having flowability at room temperature.

Further, it is possible that the first flowing medium is oil, and thesecond flowing medium is pure water. The reason for this is because thefirst flowing medium and the second flowing medium are not dissolvedwith each other, a surface tension of the first flowing medium is high,and the first flowing medium has excellent wettability with the metalparticles. The oil and the water are separated after a lapse of timefrom being mixed, the metal particles may be present in the oil, and anoil-repellent film is formed further on the circuit substrate, wherebythe oil containing the metal particles can be self-aggregated on theconnection terminal.

Moreover, as the metal particles, a solder alloy of a Sn—Bi system, aSn—Pb system, a Sn—Ag system or the like, and a metal such as Cu, Ag andAgCu can be used. Incidentally, in the present invention, in order toobtain the electric connection between the terminals by the contact ofthe conductive particles with each other, it is preferable to suppressthe growth of the oxidation film on the surfaces of the conductiveparticles to be minimum. Moreover, it also may be in a state where onlythe surfaces of the conductive particles that are in contact with eachother are melted, and a metal bond is formed on each of interfacestherebetween.

Further, the conductive resin composition may contain inorganic (forexample, silica, alumina and the like) powders for controlling thermalexpansion, thermal conduction and a dielectric constant in the sealingresin, besides the above-described contents.

Moreover, as the organic layer as the water-repellent film, awater-repellent film such as a silicone film, a silicone-acryliccopolymer and a fluorine-acrylic copolymer may be used. Thewater-repellent film preferably has a contact angle with water of 90° ormore, and a contact angle with a solvent such as toluene of 50° or less,for example.

In the flip chip packaging method described above, it also is possiblethat the substrate 14 is constituted of the circuit substrate, and aplurality of the semiconductor chips 16 are subjected to the flip chippackaging on the substrate 14.

Moreover, the semiconductor chip 16 may have a structure (for example,CSP, BGA or the like) where a semiconductor bare chip is mounted on aninterposer having a plurality of electrode terminals land), and may be acircuit substrate. That is, it can be applied to not only the flip chippackaging but also a connection between substrates for electricallyconnecting electrodes of the substrates each of which has a plurality ofthe electrodes. The connection between the substrates can be achieved bya method described below.

Firstly, an electrode of a first substrate and an electrode of a secondsubstrate are arranged in a state of facing each other and being held ata desired gap, the conductive resin composition of the present inventionis supplied into a gap between the first substrate and the secondsubstrate, and the first flowing medium containing the metal particlesof the conductive resin composition is self-aggregated between theelectrode of the first substrate and the electrode of the secondsubstrate by an interfacial tension. Thereafter, the resin that isself-aggregated between the electrodes is cured.

As described above, the present invention has been explained by way of apreferred example, but the description above does not limit the presentinvention, and needless to say, it can be modified variously. Forexample, it is described that the conductive resin compositionpreferably has a viscosity having flowability at room temperature, butmay have a viscosity that is decreased to be flowable by being heated.

The present invention provides a conductive resin composition that canapplied to the flip chip packaging of the next-generation LSI, the flipchip packaging method with high productivity and high reliability, andthe connection method between the substrates.

The invention may be embodied in other forms without departing from thespirit or essential characteristics thereof. The embodiments disclosedin this application are to be considered in all respects as illustrativeand not limiting. The scope of the invention is indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are intended to be embraced therein.

1. A conductive resin composition for connecting electrodeselectrically, in which metal particles are dispersed in a flowingmedium, wherein the flowing medium comprises a first flowing medium thathas relatively high wettability with the metal particles and a secondflowing medium that has relatively low wettability with the metalparticles, and the first flowing medium and the second flowing mediumare dispersed in a state of being incompatible with each other.
 2. Theconductive resin composition according to claim 1, wherein the metalparticles are dispersed in the first flowing medium and the secondflowing medium when being mixed, the metal particles are dispersed inthe first flowing medium in a stationary state, and the first flowingmedium and the second flowing medium are in a state of being dispersed.3. The conductive resin composition according to claim 1, wherein asurface tension of the first flowing medium is higher than a surfacetension of the second flowing medium.
 4. The conductive resincomposition according to claim 1, wherein the first flowing medium iscomposed of a thermosetting resin, and the metal particles are made of asolder metal and have a melting point that is equal to or lower than acuring temperature of the thermosetting resin.
 5. The conductive resincomposition according to claim 1, wherein the first flowing medium iscomposed of a thermoplastic resin, and the second flowing medium iscomposed of a thermosetting resin.
 6. The conductive resin compositionaccording to claim 1, wherein the first flowing medium is composed of athermosetting resin, and the second flowing medium is composed of aphotocurable resin.
 7. The conductive resin composition according toclaim 1, wherein the first flowing medium or the second flowing mediumis a liquid, and a solvent that can be solved in the first flowingmedium or the second flowing medium is added.
 8. The conductive resincomposition according to claim 1, wherein the first flowing medium isoil, and the second flowing medium is water.
 9. The conductive resincomposition according to claim 1, wherein a content ratio of the metalfine particles, the first flowing medium and the second flowing mediumis within ranges of: the metal particles: 4 wt % to 40 wt %; the firstflowing medium: 10 wt % to 20 wt %; and the second flowing medium: 40 wt% to 76 wt %.
 10. The conductive resin composition according to claim 1,wherein an average volume particle diameter of the metal fine particlesranges from 1 μm to 30 μm. 11-19. (canceled)